Fault - opengeospatial/Geotech GitHub Wiki

What is a Fault?

A fault includes all brittle to ductile style structures along which displacement has occurred, from a simple, single 'planar' brittle or ductile surface to a fault system comprised of tens of strands of both brittle and ductile nature. This structure may have some significant thickness (a deformation zone) and have an associated body of deformed rock that may be considered a deformation unit (which geologicUnitType is ‘DeformationUnit’) which can be associated to the ShearDisplacementStructure using GeologicFeatureRelation from the GeoSciML Extension package

Realizations

Data model Concept name Definition
OGC GeoSciML ShearDisplacementStructure A shear displacement structure includes all brittle to ductile style structures along which displacement has occurred, from a simple, single 'planar' brittle or ductile surface to a fault system comprised of tens of strands of both brittle and ductile nature. This structure may have some significant thickness (a deformation zone) and have an associated body of deformed rock that may be considered a deformation unit (which geologicUnitType is ‘DeformationUnit’) which can be associated to the ShearDisplacementStructure using GeologicFeatureRelation from the GeoSciML Extension package.
IFC Fault Same as OGC
AGSi agsiModelElement In AGSi a model is collection of elements (agsiModelElement object) and this may include elements representing geological structure such as faults, identified as such using the elementType attribute.

Properties

PropertyName Definition
identifier Globally unique identifier:Primitive::CharacterString shall uniquely identifies a tuple within the dataset and be formatted as an absolute URI conformant to RFC 3986.
name name contains a display name for the ShearDisplacementStructure.
description description contains a human readable text description of the ShearDisplacementStructure, typically taken from an entry on a geological map legend.
faultType faultType contains a human readable description of the type of ShearDisplacementStructure (as defined in GeoSciML). To report an identifier from a controlled vocabulary, faultType_uri shall be used.
movementType movementType contains a human readable summary of the type of movement (e.g. dip-slip, strike-slip) on the ShearDisplacementStructure. To report an identifier from a controlled vocabulary, movementType_uri shall be used.
deformationStyle deformationStyle contain a human readable description of the style of deformation (e.g. brittle, ductile etc.) for the ShearDisplacementStructure. To report an identifier from a controlled vocabulary, deformationStyle_uri shall be used.
displacement displacement contains a text summarising the displacement across the ShearDisplacementStructure.
geologicHistory geologicHistory contains a text, possibly formatted with formal syntax, describing the age of the ShearDisplacementStructure (where age is a sequence of events and may include process and environment information).
observationMethod observationMethod contains a metadata snippet indicating how the spatial extent of the feature was determined. ObservationMethod is a convenience property that provides a quick and dirty approach to observation metadata when data are reported using a feature view (as opposed to observation view).
numericOlderAge numericOlderAge reports the older age of the fault/shear structure, represented million years (Ma).
numericYoungerAge numericYoungerAge reports the younger age of the fault/shear structure, represented million years (Ma).
source source contains a text describing feature-specific details and citations to source materials, and if available providing URLs to reference material and publications describing the geologic feature. This could be a short text synopsis of key information that would also be in the metadata record referenced by metadata_uri.
metadata_uri If present, the property metadata_uri:Primitive::CharacterString contains a URI referring to a metadata record describing the provenance of data.
shape The property shape:GM_Object contains a geometry defining the extent of the feature of interest.
positionalAccuracy If present, the property positionAccuracy:Primitive::CharacterString contains quantitative representation defining the radius of an uncertainty buffer around a MappedFeature (e.g., a positionalAccuracy of 100 m for a line feature defines a buffer polygon of total width 200 m centred on the line).
FaultActivity Qualitative rating of the fault activitity. A fault that has slipped in historic time and which is likely to slip again in the future.
FaultAperture GT1R1A1
FaultLength Fault length (L) is the longest horizontal or subhorizontal dimension along the fault plane
FaultDepth Fault depth is the depth where no further relative displacement is recorded
FaultInfilling Substance interspersd between the wall surfaces of a discontinuity (JGS) generally, the material occupying the space between joint surfaces, faults, and other rock discontinuitires. The filling material may be clay, gouge, various natural cementaing agents, or alteration products of the adjacent rock.(ASTM, ISRM)
DipDirection The geographic direction of a line created by the intersection of a plane and the horizontal plane. If non specific convention is used, this angular value is in the range 0 to 18 degrees. In this case, there is an ambiguity on the dip orientation. For example, a plane with an orientation of 90 degrees from the nord could either have a dip direction to the North or to the South. Thus, to avoid this ambiguity, a strike value is generally completed with an indication of the dip orientation (Quadrant).
FaultSlipDirection Observed relative displacement direction of the hangingwall (top) to the footwall, e.g. up. Down, left, right or combinations (like top down - left)
FaultPitchAngle angle between the strike of the slip surface and the slip vector (striation)
FaultThrow the vertical displacement between the Hanging wall and Footwall
FaultHeave the horizontal displacement between the Hanging wall and Footwall.
FaultOffset The horizontal displacement between points on either side of a fault, which can range from millimeters to kilometers.
FaultDipSeparation offset of beds parallel to fault
FaultStrikeSeparation offset of beds parallel to dip

FAQ

GitHub issue

https://github.com/opengeospatial/Geotech/issues/20